“Estimation of SARS-CoV-2 infection fatality rate by real-time antibody screening of blood donors” (medRxiv; thanks, Colin!) describes testing donated blood in Denmark (nearly 10,000 samples) and finding that only 1.7 percent were positive for coronavirus antibodies. The blood had been donated April 6-17.
Does this mean that, now that the Danes are emerging from their bunkers, they will essentially start all over with a coronaplague? If 98 percent of the population has no immunity to plague, how is that different than if 100 percent of the population has no immunity (presumably, the situation back in December/January)? If it wasn’t safe for people to mix back in mid-March, now that 2 percent of the population is presumed immune, it is suddenly safe?
What do we make of this seemingly crazy low number for a purportedly exponentially growing disease that had at least two months to run free in Denmark? Here are some possibilities:
- Except in certain high-density cities, coronaplague is not very contagious, nowhere near as ferocious as we were told
- A lot of people simply aren’t susceptible to coronaplague, just as a lot of people won’t catch a cold that is going around, and, having never been truly infected, don’t develop antibodies
- The antibody tests that we have are not reliable for determining if someone has previously been infected with coronaplague
[Another aspect of the paper that I suspect won’t interest anyone:
Using available data on fatalities and population numbers a combined IFR in patients younger than 70 is estimated at 82 per 100,000 (CI: 59-154) infections.
In other words, a person under 70 who actually does get infected with this evil virus has a 0.082% of dying (about the same as the annual risk of death from commuting via motorcycle 4,000 miles per year). Given the current popular mood, however, I think any number larger than 0% will be a sufficient justification for cowering in a bunker.]
Some other studies in the most plague-ridden areas have found 20-30 percent of the adult population with antibodies. That too, however, suggests to me that a lot of people are somehow naturally immune.
Readers: Could Denmark have truly missed this first wave of plague?
- “Why herd immunity to COVID-19 is reached much earlier than thought” (models would kick out very different results if you assume that not everyone is a suitable host for coronavirus)